Biodegradable Polyester Resin Composition

Abstract

[Object] To provide a biodegradable polyester resin composition that can achieve excellent antistatic properties and surface lubricity while maintaining the molecular weight without deteriorating the appearance of the resin, even if a kneading method is employed. [Solving Means] A biodegradable polyester resin composition containing 0.05 to 10.0% by weight of a borate ester surfactant (a reactant of boric acid and a compound given by esterifying a polyol with a higher fatty acid, a salt of the reactant, a reactant obtained by reacting a higher fatty acid to a compound given by esterifying a polyol with boric acid, or the like) having one or more hydrophobic groups having 8 to 24 carbon atoms.

Description

TECHNICAL FIELD [0001] The present invention relates to a biodegradable polyester resin composition having an excellent antistatic ability. More specifically, the present invention relates to a polylactic acid resin composition which is a recyclable resource derived from a plant. BACKGROUND ART [0002] Plastics, such as polypropylene, polyethylene, or polyvinyl chloride, made from fossil resources such as petroleum are processed into food wrapping films, electric appliances, and industrial materials. Thus, plastics are indispensable and very important for our daily lives. However, it is the well-known fact that, since plastics are not biodegradable, they continue to remain almost permanently in the natural environment when they are unnecessary after the use and have a significant effect on the ecosystem, which causes environmental destruction in various aspects. [0003] In such circumstances, attention has been focused on biodegradable polyester resins. Among them, biodegradable resin...

AI Technical Summary

Benefits of technology

[0016] The biodegradable polyester resin composition containing 0.05 to 10.0% by weight of a borate ester surfactant having one or more hydrophobic groups having 8 to 24 carbon atoms according to the present invention can achieve excellent antistatic properties and surface lubricity while maintaining the molecular weight without deteriorating the appearance of the resin.

Problems solved by technology

However, it is the well-known fact that, since plastics are not biodegradable, they continue to remain almost permanently in the natural environment when they are unnecessary after the use and have a significant effect on the ecosystem, which causes environmental destruction in various aspects.

This is caused by the expectation that the polylactic acid resin synthesized from sugar derived from plants such as corn and potato or lactic acid given by fermentation thereof can construct a material recycling system for recyclable resources, though various types of plastics made from fossil resources deviate from such a recycling system in the social background that the material recycling system for saving limited fossil resources and thoroughly recycling natural resources is brought as an issue.

In addition, the polylactic acid resin which becomes unnecessary is readily hydrolyzed and degraded by microorganisms in the natural environment and is finally decomposed into water and carbon dioxide.

However, since the biodegradable polyester resin also has electrical insulation which is particular to resin similar to general resins, it is readily electrostatically charged and has many problems caused by the electrostatic charge, for instance, shedding of ink in printing, dispersing of contents in packaging, or impairment of the appearance by adhesion of dust to products.

However, in such application methods, generally, the application step is an additional step after the formation of resin and therefore causes an increase in the cost.

In addition, the application methods have particular problems such as sliding properties, inferior in transparency, and lack of sustainability of antistatic properties.

Further, the compatibility between the crystallinity of a resin and a surfactant highly affects the appearance of the resin.

The addition of an improper surfactant deteriorates the appearance of the biodegradable polyester resin.

In addition, the molecular weight is decreased to cause deterioration in the strength.

Thus, the kneading method has problems.

However, actually, antistatic properties are not sufficiently obtained by the addition of a nonionic surfactant because of the crystallinity particular to the biodegradable polyester resin and the balance in compatibility between the resin and the surfactant.

However, a suitable lubricant for this requirement has not been found yet.